It was located south of the outflow of Anduin at the Bay of Belfalas in a convenient, useful natural haven. The great cape and land-locked firth formed the port. The natives called it "Umbar" and the Númenóreans who discovered it, adopted its name.

Like the earlier New Haven in Enedwaith, and the later Pelargir on the Anduin, Umbar was one of the trading ports at the southern coast of Middle-earth, which became a base from which Númenórean influence spread over Middle-earth. In S.A.2280 it was made into a great fortress as a reaction to the growing threat of Sauron[1] and became the strongest and most important.

During the dissension arising when the Shadow fell on Númenor, Umbar was the northernmost settlement of the King's Men; Sauron, after trying to break the waxing Númenórean grip by instigation, attempted to attack the Númenórean havens and forts, invaded their coastlands, but Umbar resisted[2][3]

It was at Umbar that Ar-Pharazôn the Golden, landed in S.A.3261, to challenge Sauron and journeyed 7 days with banner and trumpet[4]. Umbar remained a symbol of Númenórean pride ever after.

While Sauron was in Númenór and the Shadow and dissidence became greater, Umbar was one of the fortresses and dwellings upon the coasts, inhabited by the King's Men and servants in Middle-earth to his will; these evil lords concentrated mostly to the south, far from the dominion of Gil-galad[4]. Umbar must have been an important point of deportation for the slaves and taxes for Númenor.

After the Downfall of Númenor, Umbar remained in the hands of the Númenóreans, in essence a realm-in-exile alongside Arnor and Gondor. But unlike these others, Umbar had been used by the Black Númenóreans, who were not friendly to the Elves or to their fellow Faithful Númenórean survivors.

Two Black Númenórean lords, Herumor and Fuinur, were probably from Umbar, as at the end of Second Age they became very powerful amongst the Haradrim, a neighbouring people. No doubt Númenóreans of Umbar were enlisted with Sauron in S.A.3429. Their fate is unknown, but they likely shared Sauron's defeat at the hands of the Last Alliance of Elves and Men.

The rulers of Umbar retained much influence over the Haradwaith well into Third Age. Other southern settlements were absorbed by the native cultures of Harad[5]

Gondor's power, however, eclipsed that of Umbar as the Third Age progressed, and at one point, perhaps around the time of Tarannon Falastur, Umbar acknowledged the sway of Gondor[6]. Tarannon had a diplomatic marriage to Berúthiel, a Black Númenórean, perhaps from Umbar. During his reign, Tarannon extended the sway of Gondor along the southern shore-lands.

in T.A.933 Gondor's King Eärnil I captured Umbar in a Surprise Attack after a siege by sea and land, although this was "at great cost." It became a great harbour and fortress of the power of Gondor. Ironically it was outside Umbar where Eärnil with his ships and men perished in a great storm (T.A.936).

For the following 500 years, Umbar was an important Gondorian city: not only a major sea-port, but as the site of the submission of Sauron to Ar-Pharazôn, and so served as a proud reminder of the might of the Dúnedain of old.[7]

Many Black Númenóreans had fled Umbar from the assault of T.A.933, to their subjects in Near Harad and prevented Gondor to take lands south of Harnen; 82 years later, in a vain attempt to recapture it, came up with great power against the stronghold. This great power availed the Men Of Harad little, however, for despite investing and besieging the fortress of Umbar for 35 years, they failed to take it, as its supply was easily maintained, "because of the sea-power of Gondor." In T.A.1050, the late King Earnil's son Ciryandil defeated the Haradrim force by sending troops by land, crossing Harnen and by sea[8]. All land south of Belfalas up to Harnen and the borders of Near Harad and coast-lands up to Umbar belonged to Gondor.

It was during this occupation when the Gondorians built a monument to Ar-Pharazôn on the highest hill above the Haven: a great white pillar crowned with a globe of crystal which shone as a star with the rays of the Sun or Moon.

Umbar and the southern provinces experienced a rebellion during the civil war of Gondor; with the people of Pelargir, Umbar supported the usurper Castamir. When the war ended, Castamir's sons and their supporters left Pelargir and established themselves at Umbar; from that point on, Umbar remained an enemy of the King[8].

Since T.A.1448, the fleets of the secessionists established under the descendants of Castamir and became known as the '"Corsairs of Umbar"' as an independent realm; thus Gondor lost both its southern province and its naval power and came in constant war against the line of Castamir. Within two centuries Umbar attacked Gondorian ships and raiding its coast at every opportunity, threatening the coastlands and all traffic on the sea and contested the possession of Harondor[7].

Umbar would welcome exiles from Gondor who were suspected for treason or conspiring against the King[8]. Umbar would also take to its side and absorb tributaries to Gondor in Harad[7]. In T.A.1540 King Aldamir fought with those rebelling kings of Harad[7]. Those were defeated by his son Hyarmendacil IIyears later[9].

Vengeance, if not swift, was certainly devastating; by 78 years later the Corsairs raided as far as Anfalas and Minardil's great-grand nephew Telumehtar punished them. In an attack he destroyed the fortress and haven of the Corsairs and drove them out. After this victory he renamed himself Umbardacil but left Umbar unsettled and ruined, apparently as a protective garrison.

In the meantime the Haradrim were "engaged in wars and feuds of their own" and threatened by the Wainriders' empire from Rhûn[10]. But this did not prevent Umbar to be lost again when enemies invaded Gondor from the east and south in T.A.1944, preventing Gondor to use it to support its forces from the sea; Eärnil's Southern Army vanquished the invaders.

Umbar had been reclaimed by the Haradrim, rebuilt and occupied and for the rest of the Third Age it became a home for a new generation of 'Corsairs of Umbar', who must have been closely related to the Haradrim, if not even merely Haradrim themselves. These new Corsairs were cruel slavers who often raided the coasts of Belfalas and Anfalas in Gondor: in T.A.2746 for example, Amrothos, the 15th Prince of Dol Amroth fell defending Dor-en-Ernil against them.

In T.A.2758 Umbar joined a massive co-ordinated attack with Men of the Harad and even of Dunland, against Gondor and the new realm of Rohan.[8]. In T.A.2885, Umbar supported the Haradrim who claimed Harondor, although this had long "been a debatable land between the Corsairs and the Kings", and when Sauron declared himself openly in T.A.2951, Umbar declared its alliegance to him, and the great monument commemorating Ar-Pharazôn's triumph at Umbar was thrown down.

During the War of the Ring, Umbar had not fully recovered from this, but could still send 50 "great ships" and smaller vessels "beyond count", to raid the coastlands of Gondor and draw off major forces from the defence of Minas Tirith. They were once again defeated by Aragorn, and the Army of the Dead. With the Fall of Barad-dûr, Umbar, weakened and defeated, finally lost its sovereignty and submitted to the crown of King Elessar.

No "King of Umbar" is mentioned to rise though the Black Númenóreans, who, regarding the Heirs of Elendil as usurpers, certainly considered themselves the representatives of the last legal King of Númenor. One can suppose as a possible explanation, that they considered themselves something like the temporary Stewards of Gondor, ruling in the true King's absence, until eg. Ar-Pharazôn would return from the West to restore his evil kingdom[11]. It is notable that all four known rulers of Umbar come in pairs, suggesting that perhaps Umbar was traditionally ruled by a duumvirate.

Nothing is known about the language of Umbar but no doubt it must have been Adûnaic, probably holding back the Elvish elements which created Westron of the Third Age, resulting perhaps in a Haradric variety of the language.[11]

Another difference between Arnor, Gondor and Umbar was that the Faithful boasted the ethnic purity of the line of their rulers, to the amount of resulting even in a Kin-strife at some point (T.A.1437-T.A.1447); on the other hand, Umbar allowed their race to swiftly dwindle and merge with the Pre-Númenóreans, something which perhaps was looked down upon by the Gondorians.[8]